Timely event-related synchronization fading and phase de-locking and their defects in migraine

•10 Hz alpha event-related oscillation was investigated during passive oddball stimulation in patients with migraine and compared with control subjects.•Alpha event-related synchronization (ERS) appeared around 100 ms and faded to zero (phase de-locking) around 300 ms after deviant sounds in control subjects.•In migraine patients, timely ERS fading and alpha phase de-locking at 300 ms after deviant sounds are defective.

ObjectiveTo investigate the characteristics of event-related synchronization (ERS) fading and phase de-locking of alpha waves during passive auditory stimulation (PAS) in the migraine patients.MethodsThe subjects were 16 adult women with migraine and 16 normal controls. Electroencephalographic (EEG) data obtained during PAS with standard (SS) and deviant stimuli (DS) were used. Alpha ERS fading, the phase locking index (PLI) and de-locking index (DLI) were evaluated from the 10 Hz complex Morlet wavelet components at 100 ms (t100) and 300 ms (t300) after PAS.ResultsAt t100, significant ERS was found with SS and DS in the migraineurs and controls (P = 0.000). At t300 in the controls, ERS faded to zero for DS while in the migraineurs there was no fading for DS. In both groups the PLI for SS and DS was significantly reduced, i.e. de-locked, at t300 compared to t100 (P = 0.000). In the migraineurs, the DLI for DS was significantly lower than in the controls (P = 0.003).ConclusionThe alpha ERS fading and phase de-locking are defective in migraineurs during passive auditory cognitive processing.SignificanceThe defects in timely alpha ERS fading and in de-locking may play a role in the different attention processing in migraine patients.